With the development of data storage techniques, various data storage devices now provide users with higher and higher data storage capacity, and also their data access speed has been increased greatly. Besides the increase of data storage capacity, users also impose greater and greater demands on data reliability and response time of storage systems.
A technical solution for building a storage system on the basis of multi-level storage media with different access speeds has been developed so far. For example, frequently used data may be loaded from a storage device with a lower access speed to a buffer device with a higher access speed, and further the buffer device may respond to access requests from the outside of the storage system. The technical solution can improve the efficiency in data response to some extent. However, since the buffer device itself is subjected to a limited space, only important data can be loaded thereto. Therefore, it becomes a focus of attention regarding how to prioritize data and how to allocate more storage pages to data with higher priorities in the buffer device and rationally schedule data pages in the buffer device.